.xlsm file is getting corrupted after using writeTo()

[azju]

Description

Hi there,

We are experiencing performance issues when using SaveAs() to save an .xlsm file with macros. To improve performance, we attempted to use WriteTo(), which successfully creates the file, but the resulting file is corrupted.

Just a few questions:

• Is WriteTo() effective for improving performance when saving large files? If not, are there better alternatives?
• Additionally, can WriteTo() handle .xlsm files with macros

Steps to reproduce the issue

1. create an excel file
2. add vbaProject.bin to the file

file, err := embeddedFile.ReadFile("vbaProject.bin")
	if err != nil {
		return nil, err
	}

	if err := f.AddVBAProject(file); err != nil {
		return nil, err
	}

3. save file using writeTo()

file, err := os.Create("output.xlsm")
	if err != nil {
		fmt.Println("Failed to create file:", err)
		return "", err
	}
	defer file.Close()

	if _, err := sf.ExcelFile.WriteTo(file); err != nil {
		fmt.Println("Failed to write file:", err)
		return "", err
	}

	fmt.Println("File written `successfully")

Describe the results you received

Describe the results you expected

I expect the file to be openable with macros, just like it is when using SaveAs().

Go version

go1.22.3

Excelize version or commit ID

2.9.0

Environment

linux/amd64

Validations

• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.